proftpd

[Rafnews]

Hi everybody,

i new to proftpd and linux, but i would like to setup ftp in the following
way:
user "jack" have access to folder /var/www/html/test1/
user "martin" has access to folders /var/www/html/martin1/ and
/var/www/html/martin2/

how can i do that ? i did not find anything such like that and i'm lost
while reading proftpd documentation :-(
thank for help.